Polished metal and obsidian mirrors have existed from ancient times, and because of this, historians have usually passed over the introduction of the glass mirror as if it was just another variation on an old theme. But the development of glass mirrors marks a crucial shift, for they allowed people to see themselves properly for the first time, with all their unique expressions and characteristics. Polished metal mirrors of copper or bronze were very inefficient by comparison, reflecting only about 20 percent of the light; and even silver mirrors had to be exceptionally smooth to give any meaningful reflection. These were also prohibitively expensive: most medieval people would only have glimpsed their faces darkly, reflected in a pool of water.

What an odd thing, to not actually know what your face looks like, and yet for most of human history, that was the case. Also interesting that the rise of glass mirrors led to an increase of commissioned painted portraits:

People’s ability to appreciate their unique appearance led to a huge rise in the number of portraits commissioned, especially in the Low Countries and Italy. While almost all the oil paintings that survive from the fourteenth century are of a religious nature, the few exceptions are portraits. This trend toward portraiture grew in the fifteenth century, and came to dominate nonreligious art. As important men increasingly commissioned artists to create their likenesses, the more those likenesses were viewed, encouraging other people to have their portraits painted.

Steven Johnson discussed glass mirrors in the opening chapter of his book How We Got To Now.

At the exact moment that the glass lens was allowing us to extend our vision to the stars or microscopic cells, glass mirrors were allowing us to see ourselves for the first time. It set in motion a reorientation of society that was more subtle, but no less transformative, than the reorientation of our place in the universe that the telescope engendered. “The most powerful prince in the world created a vast hall of mirrors, and the mirror spread from one room to another in the bourgeois household,” Lewis Mumford writes in his Technics and Civilization. “Self-consciousness, introspection, mirror-conversation developed with the new object itself.”

Social conventions as well as property rights and other legal customs began to revolve around the individual rather than the older, more collective units: the family, the tribe, the city, the kingdom. People began writing about their interior lives with far more scrutiny. Hamlet ruminated onstage; the novel emerged as a dominant form of storytelling, probing the inner mental lives of its characters with an unrivaled depth. Entering a novel, particularly a first-person narrative, was a kind of conceptual parlor trick: it let you swim through the consciousness, the thoughts and emotions, of other people more effectively than any aesthetic form yet invented. The psychological novel, in a sense, is the kind of story you start wanting to hear once you begin spending meaningful hours of your life staring at yourself in the mirror.

If glass mirrors helped bring about such a shift in society, I wonder how society is shifting with the ability, only over the past 10-15 years or so, for people to instantly share their inner thoughts and selfies with friends, family, and even strangers many times every day? Is this more “seeing ourselves clearly” (individualism) or is the ability to allow others to see us clearly so frequently steering us back toward collectivism? Or somewhere else entirely?

In How We Got to Now, the TV series based on the book of the same name, Steven Johnson explains how the wine press was used to print books, which resulted in a surge in demand for reading glasses, which had yet more unintended effects.

This is how change happens in the natural world: sometime during the Cretaceous age, flowers began to evolve colors and scents that signaled the presence of pollen to insects, who simultaneously evolved complex equipment to extract the pollen and, inadvertently, fertilize other flowers with pollen.

Over time, the flowers supplemented the pollen with even more energy-rich nectar to lure the insects into the rituals of pollination. Bees and other insects evolved the sensory tools to see and be drawn to flowers, just as the flowers evolved the properties that attract bees. The symbiosis between flowering plants and insects that led to the production of nectar ultimately created an opportunity for much larger organisms — the hummingbirds — to extract nectar from plants, though to do that they evolved a extremely unusual form of flight mechanics that enable them to hover alongside the flower in a way that few birds can even come close to doing. In other words, they had to learn an entirely new way to fly.

At the start of the 20th century, in Brooklyn, a printer was doing full-color magazines. In the summer the ink didn’t set up properly. The printer hired a young engineer, Willis Carrier, to devise a way to bring down the temperature and humidity in the room. He built this contraption that made the printing possible. Then the workers were like, “I’m gonna have my lunch in the room with the contraption, it’s cool in there.” Carrier says, “Hmm, that’s interesting.” He sets up the Carrier Corporation, which air-conditions movie theaters, paving the way for the summer blockbuster. Before air conditioning, a crowded theater was the last place you wanted to go. After a/c, summer movies become part of the cultural landscape.

The opening episode, for instance, is called “Clean,” and it sets the pattern for the five that follow. We tend not to acknowledge just how recent some of the trends and comforts of modern life are, including the luxury of not walking through horse manure and human waste on the way to the post office.

The episode turns back the clock just a century and a half, to a time before our liquid waste stream was largely contained in underground pipes. Mr. Johnson then traces the emergence of the idea that with a little effort, cities and towns could have a cleaner existence, and the concurrent idea that cleanliness would have public health benefits.

But his examination of “the ultraclean revolution,” as he calls it, doesn’t stop at the construction of sewage and water-purification systems. He extends the thread all the way to the computer revolution, visiting a laboratory where microchips are made.

The show is based on Johnson’s book of the same name, which enters the NY Times bestseller list at #4 this week. Also, I keep wanting to call the book/show How We Got to Know, which strikes me as a perfectly appropriate title as well.

The show builds on many of themes in the innovation history trilogy of The Ghost Map, The Invention Of Air, and Where Good Ideas Come From, but is based on new material with a completely different structure. Each hour-long episode takes one facet of modern life that we mostly take for granted — artificial cold, clean drinking water, the lenses in your spectacles — and tells the 500-year story of how that innovation came into being: the hobbyists and amateurs and entrepreneurs and collaborative networks that collectively made the modern world possible. It’s also the story of the unintended consequences of these inventions: air conditioning and refrigeration didn’t just make it possible to build ski slopes in the desert; they also triggered arguably the largest migration of human beings in the history of the species — to cities like Dubai or Phoenix that would otherwise be virtually uninhabitable.

Outside of the nature documentaries like Planet Earth, I haven’t seen a decent science series on TV in a long while — most of them are too slow with too much filler and not enough actual, you know, science — so I’m not getting my hopes up too high, but hoping this one bucks that trend.